SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aa5c02eab9ab73119a0372a7d5be57b2ce66b9a54047faf82d7defcae46c517' 
  AND token = 'WRAbjOATpzeRwAdzXusaindJzyMkFITkn8VVxfZhrKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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