SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '558a80a0ace8570853d325206ff1f2eb2c325c620dca1a28344cabd1b9e67afe' 
  AND token = '+fhGpY+XtQXG/FYlkwZVnBLIhPOsn5avla9K804wBpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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