SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c70ddb1dc815cf7e263751f40ffb9c2b24a61f6dd44dd07f17731d7b809c9e1a' 
  AND token = 'tZcp+yKZe+vSMosjFT8qE9JVLmm5oeN4zBzZF1QYbD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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