SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4946c115663402c5a294e6e7d58cb57492dcbb2fe24106951d5101de087a4eb' 
  AND token = 'mjk/xPvhIJULsQlRQ+iCDGtoCRvkk6Wp62HxU8u08vE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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