SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fe9dcaac113d3eb2a5d1181fe242cf69a978115752f69326f619aacd3ef0c6f9' 
  AND token = 'L6K9CBk+KoSbUCVkr9Zaxq4AWLqJh9k1rkoSt5RyOa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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