SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9b1800484787cf7440697249850cea812833e64d48197a85c9c58cd09a865ae' 
  AND token = '7mo+h+myac3Vl5Uujqh4gxEmcEZlsKK5rESkYjFxZmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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