SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f1f861af8fe3d930c107ed5128db0e9a68087ded39b481cfcb3452749785bca' 
  AND token = 't0sQCZ366jJd3eXZBG+DZCoMxOCCmCHyWmMuZ9ruUcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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