SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd9a47d1a4ab0aef5b5113f9a6a91a456718ffc842b7f125b955541f491189010' 
  AND token = 'r7gurET9WwBEBbvRRip34WG6FGT8M8yHqKGAJpCAqV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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