SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2b8bc72a16859bc5384830f8d5c468b6d1ea9d625df39e11bd2074c48a9ccf5a' 
  AND token = 'evwJdScMJsKBzjDr4BgsGV1NLhiLBrriowCpDq4NB88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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