SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44e47bacc406800adfa6e9dc44203b782a9bc6090513146ccf5fec2e9d730f2b' 
  AND token = 'ChJQOHkdn6LffKf8hTo8YZ9RA58PnNYrn2wk4PQWvyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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