SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b152684a42dd00825616138647f4a1b7cd2b43f9995765f27b6a027c86243dad' 
  AND token = 'XXC16rdwNMeWHUj3qd5PKSI+U6loFyhqT/YngP0XBRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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