SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c9e9320de2173e0fe0e9bf1f0aaf1f5b856628dbf8a25933748eef9ab2e72f6' 
  AND token = 'SeKi5EwDd7WhbhEq1zswN2lHpPjeGkpFJuT57ybBr6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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