SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee4bc92903daa47b6cc6ac51dea509e97f51b33a0844c3c0f1956fa9d97042a7' 
  AND token = '25SxwBg1DjLofTrNSVKAs5kYqctHjZPYOtoaONzxf1Y=' 
  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"
    }
  }
}