SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c593dab264cc107653d000ffa612ed5c16d1a3450725cca2ae1e085dfb501a6' 
  AND token = 'P6YgwEJjldyMPEVXIpTiwrLPOyJYsEu8QzYhhY9jP0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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