SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e5e9c521d5c38a1c9b8fb87f995e4f7e62b5f4b84b2d75bea9cf893704a036a' 
  AND token = 'VJA8/BljfLb4LVb8ZFXHn6oVYyfvuTYvFFvYNYFF1iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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