SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985f952a9d6d4de14d38effc47f249bdf2309c82c9dabab68de8640a3cca8380' 
  AND token = 'mpZHzNkFj1C0gsJuyGUDckkhgnhdYw6HQlY2D2jkMtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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