SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818beaa8cc42fef6030cbb7cef8b0f10dc50fab006a9bb0471495c31d0f5b84a' 
  AND token = '1fiPda9HR40Io/MH3J5vAG2pfDRPmag4HKw6M9jlOxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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