SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a1fee8b44cb172760601e7d3293736b24bde64007c73eba746c645c7034f62d' 
  AND token = '4Vcw3YOTBczSVlxovTqOcW3rohTKCoS/HSd5OiKrwNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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