SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72df99b7cd94e21dbb530ce420bb64ba564429c780acc748d542bd784b98a52e' 
  AND token = '94TCVFNMEHmMtFFyAIhstKPPd0i43vK2pXTfADMA61Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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