SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be54611c556d6e96872b10be487c1a43acdd9f926f8a1910672a3c8e745b18b1' 
  AND token = 'ygJPFVgc5Bq97scyzixqoWnBxw4h5FxfX46YjgFDen0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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