SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bddf99be1ad370e426f28d2e56749dfaa38c9e59489ad98aeb7fa6a708d20ad' 
  AND token = 'ei+ojbNp22yVp+IiFMkMER98ZmV6Pdgizcrmq0Lkg18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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