SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'fb881eb4a3eabf60aca4384fcc6a35ce0f3c9e8ced688a372d9b6d3222882c84' 
  AND token = 'mLw0YCwRpZR+orfx6/vi021+u2BWPBvMZ4s9524I57M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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