SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c16531f911819940835d9fd253d68724716f42e9a898c85319cc16b4c8f17be7' 
  AND token = 'mVuUJ1yeJqYrIBf1lW5tfVdoQcGHT1vjpEasaqWmjRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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