SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f15531e8c8cefe40b72c65db4d195e0c0772b62e78769afb3095ffd0f7d9d574' 
  AND token = 'reP3NJH+4iahdW9AkSjyQoyg+708lwQLj31oCZdGBU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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