SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0c7be1e17c495586fa7a8828a79ce52b29b8c0656ff793ea8b44bfda26b93cb' 
  AND token = 'h4QGwA5TECIEMeqmir12Hn9FAaxIugbAYmcWMWMOKMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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