Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c3e63781114a692d602757252969b80836ad771ef39f1f86a0048e4e72cab2d' 
  AND token = '8w4xHcEqilGGciWcvMGXjSngexCtH12a1IyrpThQp4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}