SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ccdcff6c0ca4f25c92e19b3b6e37336ec79fb07f148d04241b2fbe270862a24' 
  AND token = 'AOrHiVsjTEIWSHUR8ioICbXxUQSkI8l7ibybE9etOy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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