SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a232dcf11225cb73c35c309794b36a6dd8abba284da71695fe8b145068d6ce55' 
  AND token = 'BCPxJFpqsdqDqr3G1Bou0C/TPKj/jk0kjWNe9ZnaX9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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