SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8107190ae0acfd7ca6a601138dd9a51efae25bc618ac08e9ff57fce43cfa7e2' 
  AND token = 'dmAVCnardPsuC8bAh80jFvhwI5QZdbzT9izYDen5jqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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