SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2eda449146f8ed289b0e65d75aa7af21ffd3181fc6cf65489979e6cf4276f44' 
  AND token = 'C9EPGV01zkgCPtQqq5EyySx1wv+eJdJ+f2BHXo5ZX9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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