SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0729f962acdf57ff10e72da7a8521376c770eabfcce638c3df14258d25c8e324' 
  AND token = 'cjahMSqSoYOvy7f2IVScO/FvcU2uR3aXanO6PFsJljE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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