SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'eaa4826371b8c4b9551788031b6a6fdafada697fc4dc370750fbb9915208d5d7' 
  AND token = 'mPkWkmq+XCCdeNId4aDqFvl1rv80KFUdihWyhJUuF6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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