SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'aceb4f42bf58d86fa37b225f9d204dac279f42093d877535550277c3cda549d5' 
  AND token = '4Exp4e9Z34UNrGqKaHk6iYvFMvD4/HWP5IiZS4jhhUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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