SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30df5ac2481320583c5887b9e7a114cf114a9520050158d2af794b3973bdecee' 
  AND token = 'Wcbw4Qfs64ZhsDwF92R1SLaszyRKL0sMq7JPsV2hZFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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