SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeee0dd08817e7705ab9a43a08da4bef3e23835116b93ba461f41491bb781873' 
  AND token = 'It3Mvccz/y9jR/dk5Pa4dkEI5wCA9akg5+82+T/GK+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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