SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f22cd7c72c13eb1a06c0c80649bf7ae902d0f5562e6a256dbed2987a65b1bf5d' 
  AND token = 'hLiAgjSFIjd5ZrbbKbhYH6v7BywFHTVbwIG2gKnC/dU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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