SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06531221fab7b271c3892055fbd279d0ac69408e03a2ce64f483c21363013f21' 
  AND token = 'TF/+QbMc4FnTtDSX0FrL24qmNHHpjoF+/0K9gGv8fU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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