SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e04f62c8f4a0b619345a36c67b02c4ba49ffe4d3b092eee8a0395d51261664cb' 
  AND token = 'dUifHWgh72BugJ2/e3Y4b88MLCpBQ4q5LnJJ/UwD0/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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