SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3c52ac648a04ed2fe4020b982ce260404645a273b3bda0afde3273bc2439ed53' 
  AND token = 'B3xoYGfq0Br8RdjpLvceFr/eXgeiOW9P5/ZL8jTcuy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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