SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd79f98586c6991acbddb4a79b33ca1a9da4203d3219f39bb10cd0d7b45ef920e' 
  AND token = 'q1u245kXQE3wXMYHrnOWdhwR7R88xMi0MFE1zgPyG0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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