SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c44d87a5099e00ac51421c7cc9324bca90f97134fdb5fb699d24c01c5dea6e02' 
  AND token = '5MiOzgqWj2VqNvt5ebOWjoYidUu5rJIrIvgohnsAl9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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