SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f696b4916a31d91f3a1e10fb1edd6a09b999836ed641accf9c85a8b488d2a96' 
  AND token = 'AHBsjr+eWZc7PdDPphY/KN8bY+0YMYWhbYRB29FV6U8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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