SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cdf8405518ad1e23872c7305d040dfa77e5e5891971de61176f41c2a8b278c7a' 
  AND token = 'nffXD5WKvZl4b587UIOH8JuVLSFG6f3uqLXjwsEOa6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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