SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1a6dff1de4cc83db7a329897bfae3af73be4dc79d5a4d299a7a35259f1c25ca' 
  AND token = 'JlYaMPuUira+t9uW0OU1VSZnpGF26+Eep4tlkeD52dE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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