SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4283ec91927fb9cfdf2eedecae32ae98189e7896a3331cae0a2bb31b75c27753' 
  AND token = 'BcCmEvaNzPKK2cDSd6yidg2eKjux3uam46h9crAkNuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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