SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28e152f0ecbfe80ff974efc8e2d9a682bcb7ef6fe06958b7b793540eb83e4414' 
  AND token = 'tgTVYcfjECq82YkXSxkOw6ty2cntOzrZnjy26RhaA8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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