SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ecb178cf6a72c0f9723c76215a704a037517303445aa63dce055aad9f48d662' 
  AND token = 'FsAcVxz1rgu54pPE3ajgZyCTcnPZnAqnP3LRtUaCFaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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