SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18ede5965d7f7c9fb26ad854b890ef3677463a1ccf9a13e1e4b00b30f4156fb2' 
  AND token = 'ktDj/g1yHOmxVZsYyWQJbrKkX3A8WzQhLOOkOGnrgV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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