SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f2242da6ce4c9e391f71359c01835f9eb43932610d6ad9f270a8183d2ff573f' 
  AND token = 'mWipEXCq6TPHaPNNIqrP3DH4i2F3zvez5z7NYeieRvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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