SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '627595d80a54dcceb1bb52ea1b7fd2a7020dc5e160cd3cc87cf4ee297368a566' 
  AND token = '63HoofF4aVUQmQMzFp24O1UJRDedjDI+vktSAj6Auj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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