SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e3b8fa9256ef2407f7d18aaf09b2ac888c96c2971285e9cd56fe3e2de927427' 
  AND token = 'kKf99yo/jJ65xvW4VEFKGdADiuUFFEHgWJWZTcwhq3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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