SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '965ee21085f66db2651315d0a087443a2c88152b29368d16d0109c5ebc25152d' 
  AND token = 'caFz1NL86QBBvvAuoi4nx4I2duO6hKhM+mFnXjFtdDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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