SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a09a61ceffe4fab791e940caa369e30262ffae6aa4fd863dfa1178ffa651d225' 
  AND token = 'Y3R5vSktos59l4VXbqkGrWD1QxGtRjgZn7B9s/PHov8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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