SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33ba10d71c581f42f912842c27382307bdcd49cf8ad564b9b1f2dcfea6e1be2a' 
  AND token = 'MSd9wNiQv9I/LK/7tqQG+Q4N/gGhCWAU2emwfiDtzGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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