SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7f758f251367bb0efb26a08dcca8ad8c2b3bdf42bc894d8ecd61195a6dbcbfd' 
  AND token = 'sT/ve76U+xDQs6NV4eluiqlJDbwi8c/KMdegy0urBFw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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