SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8a06664c8299e4a19f87c76758ece4af44afb036868b0118a2c039a2fea6b56' 
  AND token = 'LYqUKEwOpBk6figVw0rLpH50tbBooVbwRbSFvSaEx7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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