SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0d3d742eef45bc8eee59911819a29b463b5325981713f1936d3c667d9ad59a1' 
  AND token = 'uxjJI+JEEtLZTszIL6qWYwuTZnT7AFloKkrQjzf6dEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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