SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd175dcb34230572bd18dca0c23ebe0fb30b88b350bbef3c81ba969a8cab3b5c4' 
  AND token = '6RpfXpyASnoYgdLd2RDNdBdbgygr/p8tX8AfsnmqHoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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