SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b5fe22408aa9875c64684b7961cf14a0b56752224a210091495cee676696ec3' 
  AND token = '6AI1zXDCtJU2Yyu2dLxs+emsw3h4Vt0/DZofMKL08SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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