SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7af7472116bd0918f71a6d558644ff90ee9eec387e1af0d240c1b9b69ff90538' 
  AND token = 'RNtX1ZUx/kDFFbrS3Z95w1d9TE0jE3MEQmrGKzvK+6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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