SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca8dac9d212afbbcca40d695ca5564b4ecd6835830a7bcc636fc098c03a09201' 
  AND token = 'xY0JJa1dmvYJWBXBdbDkjrzGQxQA2vttH4EMiXm5+3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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