SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '807b61d3710f60acfb4de20a8b3f3fd32bb1caf264c0c33963d22fb0387da1d2' 
  AND token = 'xoRyyl2KC/TssNeZLBEn2/82sgV0KzJ/YgHkc2GQXhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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