SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9b4765d5150da5eaec72e37f73d16f624a4b17d56817fa106a1b079316995a7d' 
  AND token = 'snnITLDdJ7hgrpvOeRchMiOdck17tX8+A0Nr/1ue5TU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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