SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824a9193d81d000ed8c675ac17131ffe8b776be9289b0435f26c4c05b534d03b' 
  AND token = '5AhQwTX62eRxFD4PxzQ6EgOWqrx7dvS9BspmCuEx5KM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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