SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca93e69fbd1f2af2b8ba9ce19bfe7044a208b95fad9c566d737dc0b19eed4033' 
  AND token = 'CcfzyPhpwIug6Y6moYQHGgHpsLnn//u/f/laiKQq4Ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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