SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3559b85ad7557f70eaa4ef5a0353d6d84dde520ae635ba2ec82141f5f8e6b961' 
  AND token = 'mjmok0dFLtCjrgahVWf9pZgY55SH1vivu5v3XSG4fmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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