SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1386f788fe85e3b5e15872efd6c0d55ab24c096293db9a1eab89003b261567f' 
  AND token = 'RZhrOUljI9MNkhfVXXqMI/eEb+zi4cPwAHIzphpJDOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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