SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe2b7dc43ca023e0e54644451013fda270e22a318953b195b194fe4d99169473' 
  AND token = 'IPIAob7S0cGQXjxkf+GvZu2uO8E3VWY2f3WqvmQdskk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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