SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6534eb0175f7b1a4ce0807a007b57f5a0c427cb95ca2ab6c733682a574f8e380' 
  AND token = 'jumPradnWFl/IAKcvaHdcZTPxXWKXk+TwfjngBdgsHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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