SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fc8a389e7c95f5e936848c9dc4af3388eb9e6c1df0668d41b82b112392cb7c0' 
  AND token = 'QS9ONSKUJkqqxhBRoJAbge12i7YBXvJWUe6UZZXegJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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