SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f1a158864fa1d9e239ada962d84829b1270d6c123cd30ee37eed74d36de99d3' 
  AND token = 'xjzpY+hW79p7KQuKcIYAvLvmyR+/nRPdmwMLiOQ/Eas=' 
  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"
    }
  }
}