SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72a71acf36c6f2026662edbe48528b756616fdef82d6e7713affa4343a4982c0' 
  AND token = 'JW2Uth8X9t9rFidweXRFgT8U+h5v2U/YB8+EAR3rdEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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