SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1369b8fc553f959c662a789b3add11372a017595f1aebda7d953248dc84007e' 
  AND token = 'Y38F4GyDpO7OPD+CKi7UmYSnGTqFGt7J5ScbAVgDumQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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