SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80f34c8cc045d9feaf2cb42f340ecdcf02d8d5ba23ccb5e1726a82a4ce2c6df5' 
  AND token = 'tVUs7mOhRZTD81+NitPMCzjltQtEJealdHJW7MO/KWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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