SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5362bb08ec62859db53cc06d9136dca8e4a3932ab2b67bfafa2cb80373dc477f' 
  AND token = 'xOfuMCH7yRu0dTwLxjM2Kh9PDw4wbjSoUFlVenB5GiM=' 
  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"
    }
  }
}