SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d78a22a7bb2d31a25a2010b9317ddb8c6ea7912e27c6201a7be7e1b0019b3d2' 
  AND token = 'H8KOG3PAyDPsCPFnMbMBhcrI2vyL97xLO+NEUdCc9Gw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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