SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eba7261ff1e8f54ad60c8e81316bb2aa7c812a01c69eeddfb1172a436676530d' 
  AND token = '4qtwWMWaIBFGw7+2+DpHjtrtj93hGCERFoXnIEVwZGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}