SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5642d61ad9a91d773e499d75f8f395fe6bc13f7be173691f6e795f8830e000c6' 
  AND token = 'Ms+MhlzJRwO7NiETvQVIKb+6T2G1zgP34qIc+Gk7CLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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