SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8640fddfc568321b63943885cf0a30df3280965768898efb2c92218afc05e7ba' 
  AND token = 'rheDmaD/zCJKREZoQyNBV8x6VkTQUEd7kTM7/fGO1zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}