SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '340245e04a59aa929e9c5ead6e189d89e75cd3e407b75ccd58f45ada7803db72' 
  AND token = 'PAORHOgwGY8qmnTfnV1tZO2KnCYmLCkhFKGqpQKZ+60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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