SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dfc3b202eab3ff03c2f772fac7308196d528ace7efc1131940134e5ab138128' 
  AND token = 'B4VyYWgdm2JfFiEuzrW05ucKeJPtRkj+BjUlkYy9Xw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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