SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '19b3d73e4435bdf5506a44fe4355a3541126dd7dded82b10ec7e90c49f79e443' 
  AND token = 'LvmueaxnrorU6nJjJqZoDEFT4rlAdbH0KqTofM4Ib0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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