SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c12ed283bc50a2f686643cfc28d9675862d866651d5528f67040f09f012941d2' 
  AND token = 'zmTbBHWRjHZ9HHaHStRDva4H7SjLV6/nw9XdjoBkNfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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