SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e511121bf26ca7fa51a9a648af6a72a35d8e0ce44c59a3bff2cf84b1d2f8fb30' 
  AND token = 'XnTJ24Eb9f17F02K2GX19MtKlCFHI+1yJ0EBYQ7vEQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}