SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b86429f738051bd35bad5606b07383c131899dbc12f095609c9823a9d73085' 
  AND token = 'lqAAu7R1S2FrbGWnf+d3pzlCDQrFbkxsebUvsPuQR5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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