SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '380029c49ad81336f991e5ffa8a943d3c06db4cdf929e07dc2902225f6a77c4b' 
  AND token = 'gtR741McdHjjA0F9OTmxa2MzIeQSo4ZOOGHXwFFBhY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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