SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfcc3319eec62ca2732340ac17848897745e2b5cdd68b75f3c296d4d60e76de9' 
  AND token = 'Pyj6J7FyDTgbaZLzF4dj0idPhvXX7dOszQlFkFXsUSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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