SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '952cc2b4c10d9df99746dbdf3bba8b487532274d4db7ef1384e62e4ea10d5cef' 
  AND token = 'mfG+D9VVaGNLqGYz6MzPUrjnFOsAPQrZIsaIxaSWlPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}