SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3cc17c840d03828d80dfbff60b88ad56b5480f3ed68f7630917f155afaf154e' 
  AND token = 'VKmqLeowKtJWevs7rZ1PZDinSJI+0GKG1w6Oz+nZQbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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