SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3daaec70b5836da9ba3924773a7b8dd23326e3832ada6ae09bfaac5975fb69fd' 
  AND token = 'r5nfdgmrW2c6HB5zJXeoFb1NWNRFAlIOdnrK5nCCO8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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