SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29cef41aefca86b2cd035aa19fcf568be978af2bb564f963981ea40ab9094afd' 
  AND token = 'Ja9Gkx5XiRnQi1ZsKvNX451Dizy/+rBVEyvvo707RU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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