SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ed449296afff1fe315fb6d0305412211f0acbd44a747d6557e4c103c0186efc' 
  AND token = 'sv9L++N4x8f3vwhDoHy5du7cTBs09pQVIJLxOIHcy2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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