SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8464926c5eb2ab21b083c0ffc77ff15f0ee069e29874c12fcc6d07d1efc2bed8' 
  AND token = 'Cfi5/N0KrlGLBOaEODXFI8lJL0z5jXN7zYZY6d0qWDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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