SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6597bcb4b7762ed65f8e37dd2af30e6242d67952cbd002da6af8fdea9c168261' 
  AND token = 'wAlYAfXOWgIiradcOF+m0nes385Fydh2iYuCcF8hRXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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