SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc7b222cb3304eb71624ade56aca178bf20951dfdfcceaf845ee3ca3982ff912' 
  AND token = 'Izd3SJpJy5YddS2wprFiDZpkvkQUzAhHtXNyRKs/HKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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