SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd66fca399a053beb045c13ef216c95d8955c0729c47683a2934503d4b313694c' 
  AND token = 'I0xILzD3p6w0GJkX59ZG+QQQlNMdRHoxNncga00CPhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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