SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57ceebf27981f1762ba1874f30af28c0d325edb4f7380e4951e56f128f9b553' 
  AND token = 'Afta2eYCarPe9fAWHSKfUSyuycHW/JdclLXqkCYuvzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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