SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7b2fbfcfcf6848ad547b5dffb7e2bcbe692decbae8f1989ceec362079ceab3d' 
  AND token = 'VYpOykYFWB4FxdAgS4797vOOi/hr/f6aLSxziQMutq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}