SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '141ea3741b7c086019ff655e813458ca3c324803bec2b626b0b9460d9d6fec85' 
  AND token = 'U6C06Q5zknuZh2Afrt+Tvpt/VEyYRxeeUveKqXQ0wjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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