SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb668260ac95268a7947ed84f9dc616bed95fb0ab92f146305088b7b6d24894f' 
  AND token = 'QDfs0C+KGQNnZ+1mm94zCyML6nNozVVXZfBgI1svbBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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