SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dab8d8901603d1cf70feb0af78fae0a93f269e516ce599dfbbb84dd8c10f79d' 
  AND token = 'MgizSRThUUarDvwWsUunGzJ5rxmprDIg8N65A9OZwyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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